import { Meta, Story, Source, Primary, Controls } from "@storybook/addon-docs";

import * as stories from "./table.stories";

<Meta of={stories} />

# Table

The table component provides a comprehensive way to display, sort and filter data. It consists of
two portions, a UI component called `bit-table` and the underlying data source `TableDataSource`.
This documentation will initially focus on the UI portion before covering the data source.

<Primary />

<Controls />

## UI Component

The UI component consists of a couple of elements.

- `bit-table`: The main component that creates a native table element and applies the table styling.
- `header`: A container for the table header.
- `body`: A container for the table body.
- `bitCell`: A cell within the table. Used for both headers and content.

### Guidelines

- Always include a row or column header with your table; this allows screen readers to better
  contextualize the data.
- Avoid spanning data across cells.
- When a cell contains an interactive element, the whole cell should be selectable and trigger the
  action not just the element the cell contains.
- Be sure to make repeating actions unique by associating them with the object they relate to.
  Example: if there are multiple “Edit” buttons on a table, a screen reader should read “Edit,
  Netflix” for an edit option for a Netflix item.
- Use [Virtual Scrolling](#virtual-scrolling) for large data sets.
- For bulk menu options, display a 3 dot menu in the header. When multiple items are selected, the
  bulk menu will contain actions that can be completed in bulk for the selected items.
  - Note, this may result in some menu actions being hidden at times if they are not applicable to
    the selected item
  - Clicking on a row’s 3 dot menu will continue to result in actions specific to just that row's
    item

### Usage

The below code is the minimum required to create a table. However we strongly advise you to use the
`dataSource` input to provide a data source for your table. This allows you to easily sort data.

```html
<bit-table>
  <ng-container header>
    <tr>
      <th bitCell>Header 1</th>
      <th bitCell>Header 2</th>
      <th bitCell>Header 3</th>
    </tr>
  </ng-container>
  <ng-template body>
    <tr bitRow>
      <td bitCell>Cell 1</td>
      <td bitCell>Cell 2</td>
      <td bitCell>Cell 3</td>
    </tr>
  </ng-template>
</bit-table>
```

## Data Source

Bitwarden provides a data source for tables that can be used in place of a traditional data array.
The `TableDataSource` implements sorting and filtering capabilities. This allows the `bitTable`
component to focus on rendering while offloading the data management to the data source.

```ts
// External data source
const data: T[];

const dataSource = new TableDataSource<T>();
dataSource.data = data;
```

We use the `dataSource` as an input to the `bit-table` component, and access the rows to render
within the `ng-template`which provides access to the rows using `let-rows$`.

```html
<bit-table [dataSource]="dataSource">
  <ng-container header>
    <tr>
      <th bitCell bitSortable="id" default>Id</th>
      <th bitCell bitSortable="name">Name</th>
      <th bitCell bitSortable="other" [fn]="sortFn">Other</th>
    </tr>
  </ng-container>
  <ng-template body let-rows$>
    <tr bitRow *ngFor="let r of rows$ | async">
      <td bitCell>{{ r.id }}</td>
      <td bitCell>{{ r.name }}</td>
      <td bitCell>{{ r.other }}</td>
    </tr>
  </ng-template>
</bit-table>
```

### Sorting

We provide a simple component for displaying sortable column headers. The `bitSortable` component
wires up to the `TableDataSource` and will automatically sort the data when clicked and display an
indicator for which column is currently sorted. The default sorting can be specified by setting the
`default`.

```html
<th bitCell bitSortable="id" default>Id</th>
<th bitCell bitSortable="name" default>Name</th>
```

For default sorting in descending order, set default="desc"

```html
<th bitCell bitSortable="name" default="desc">Name</th>
```

It's also possible to define a custom sorting function by setting the `fn` input.

```ts
// Basic sort function
const sortFn = (a: T, b: T) => (a.id > b.id ? 1 : -1);

// Direction aware sort function
const sortByName = (a: T, b: T, direction?: SortDirection) => {
  const result = a.name.localeCompare(b.name);
  return direction === "asc" ? result : -result;
};
```

### Filtering

Filtering is supported by passing a filter predicate to `filter`.

```ts
dataSource.filter = (data) => data.orgType === "family";
```

Rudimentary string filtering is supported out of the box with `TableDataSource.simpleStringFilter`.
It works by converting each entry into a string of it's properties. The provided string is then
compared against the filter value using a simple `indexOf` check. For convenience, you can also just
pass a string directly.

```ts
dataSource.filter = TableDataSource.simpleStringFilter("search value");
// or
dataSource.filter = "search value";
```

### Virtual Scrolling

It's heavily advised to use virtual scrolling if you expect the table to have any significant amount
of data. This is done by using the `bit-table-scroll` component instead of the `bit-table`
component. This component behaves slightly different from the `bit-table` component. Instead of
using the `*ngFor` directive to render the rows, you provide a `bitRowDef` template that will be
used for rendering the rows.

Due to limitations in the Angular Component Dev Kit you must provide an `rowSize` which corresponds
to the height of each row. If the height of the rows are not uniform, you should set an explicit row
height and align vertically.

```html
<bit-table-scroll [dataSource]="dataSource" rowSize="47">
  <ng-container header>
    <th bitCell bitSortable="id" default>Id</th>
    <th bitCell bitSortable="name">Name</th>
    <th bitCell bitSortable="other" [fn]="sortFn">Other</th>
  </ng-container>
  <ng-template bitRowDef let-row>
    <td bitCell>{{ row.id }}</td>
    <td bitCell>{{ row.name }}</td>
    <td bitCell>{{ row.other }}</td>
  </ng-template>
</bit-table-scroll>
```

#### Deprecated approach

Before `bit-table-scroll` was introduced, virtual scroll in tables was implemented manually via
constructs from Angular CDK. This included wrapping the table with a `cdk-virtual-scroll-viewport`
and targeting with `bit-layout`'s scroll container with the `bitScrollLayout` directive.

This pattern is deprecated in favor of `bit-table-scroll`.

## Accessibility

- Always include a row or column header with your table; this allows assistive technology to better
  contextualize the data
- Avoid spanning data across cells
- Be sure to make repeating actions unique by associating them with the object they relate to
  - **Example:** if there are multiple “Edit” buttons on a table, a screen reader should read “Edit,
    Netflix” for an edit option for a Netflix item.
